package com.itheima.duotai.homework.homework5;

public class Computer {
    public void kaiJi() {
        System.out.println("笔记本开机");
    }
    public void guanJi() {
        System.out.println("笔记本关机");

    }
    public  void  useUSB(USB usb){
    USB usb1=usb;
    usb1.start();
    usb.end();
        }



}
